The major goal of the proposed research is to evaluate the vaccine potential of specific schistosome molecules. to accomplish this goal we will take advantage of the fact that in concomitant or attenuated parasite immunity, there are species of antibody molecules that recognize determinants on the surface of the schistosomule that mediate a schistosomicidal response. These antibodies provide appropriate reagents for isolating relevant antigens, when used in conjunction with recombinant DNA technology. By isolating the DNA encoding an important antigen, produce reasonable quantities of the antigen in prokaryotic or eukaryotic vectors for vaccine testing or create a modified antigen that may function even better than the native one in producing immunity. A second strategy will be to take advantage of the fact that may protective monoclonal and polyclonal antibodies recognize carbohydrate epitopes. These protective antibodies will be used to make hybridoma-derived anti- idiotypic antibodies that mimic the carbohydrate epitope. By assessing the efficacy of identified antigens or anti-idiotype antibodies in protection experiments we will be able to identify those schistosome molecules that are potential vaccine candidates.